(a) Field of the Invention
The present invention relates to a locking device provided with switches associating with the lock of a room to guarantee security in the room left absent and to control the supply of power to the room, and more particularly, to a locking device capable of being easily locked or unlocked from inside and outside the room.
(b) Brief Description of the Prior Art
The inventor of the present invention proposed a power ON-OFF device used for security means by U.S. Pat. No. 3,803,575, German Pat. No. 2,343,594 and Japanese utility model 1,193,002. When a room is locked to leave it absent, said device is associated with the lock of room to switch on the power source to an alarm means. The alarm means is automatically made ready operation unless the lock of room is forgotten. When the room is unlocked, the power source to the alarm means is switched off causing alarm not to be sounded when window or the like of room is opened. This device is advantageous in that no fear is caused that alarm is surprisingly sounded when the power source arranged outside the room is forgetfully left ON to the alarm means and the room is unlocked to enter, which was often seen in conventional devices prior to this one. Therefore, this device is extremely useful for security means. However, assume that two or more persons are living in a room and that someone goes out but the others are present in the room. When the device is arranged in such a way that it can be operated same way from inside and outside, the power source to the alarm means is switched on associating with the lock of room from inside, so that fear will be caused that unnecessary alarm is sounded when window or the like, to which sensors are arranged, is opened by any one of persons present in the room. In addition, even if central management is tried by a central observation system arranged remote from rooms, to each of which is attached the device, it is impossible because the device can not tell whether the lock of room is done from inside or from outside, that is, whether the locked room is occupied by some persons or left absent.
In a hotel, apartment house or the like in which travellers or persons are staying or living in their respective rooms, it is essential to guarantee security and prevent any accident by recognizing whether each of rooms is occupied or absent. Therefore, each of rooms must be kept under complete observation. Further, it is also extremely important to save as much as possible the power consumed in each room by turning off the power source to each room absent, when saving-energy becomes louder these days. The locking device of the present invention is provided to meet these demands.